Link between cervical microbiome and cancer discovered
Bacteria may play an important role in whether a woman develops cervical cancer, according to global health research newly published by scientists from the University of Nebraska–Lincoln and the Ocean Road Cancer Institute in Dar es Salaam, Tanzania.
Part of a growing body of research examining how the “microbiome” — the composition of bacteria living inside the body — may improve health or contribute to disease, the new study found a significant association between the composition of a woman’s cervical microbiome and the presence of pre-cancerous lesions on her cervix.
“There are certain families of bacteria that appear to be associated with the higher grades of pre-cancerous lesions,” said lead author Peter Angeletti, associate professor with the Nebraska Center for Virology at the University of Nebraska-Lincoln. “What we know so far is that there is a relationship between the virus commonly associated with cervical cancer and the microbiome.”
Although more research is needed, the findings offer a hint that one day cervical microbiota could be used for cancer screening and diagnosis, or perhaps cancer could be treated or prevented with probiotics or antibiotics.
The researchers used “deep sequencing” — a way to genetically identify thousands of bacterial families all at once — to identify the bacteria present in samples obtained from 144 Tanzanian women who underwent cervical cancer screenings at locations in Tanzania between March 2015 and February 2016.
Cervical cancer is a particularly devastating problem in Sub-Saharan Africa, where 8 percent of the world’s women older than 15 account for 14 percent of the cervical cancer cases and 18 percent of the cervical cancer deaths.
Of the women in the study, 126 had tested positive for Human Papillomavirus (HPV), 41 had tested positive for the human immunodeficiency virus (HIV), and 50 had been diagnosed with high-grade lesions likely to become cancerous.
According to a 2012 study, HPV is responsible for 99 percent of cervical cancer cases. HIV is strongly linked to increased risk of HPV infection.
Published Feb. 19 in mBio, the study found women with the high-grade lesions had a more abundant and diverse microbial mix in their cervical microbiomes than women who had no lesions or less serious lesions.
Angeletti said the data suggests that Mycoplasma bacteria, in particular, may help promote the growth of HPV-related lesions. Mycoplasma is a group of small, typically parasitic, bacteria that can cause pneumonia, pelvic inflammatory disease and urinary tract infections. Some forms of the bacteria can be sexually transmitted.
The study was supported with a $3.7 million grant from the National Cancer Institute. Members of the research team included Charles Wood, director of the Nebraska Center for Virology; John West, research associate professor at the Center; Samodha Fernando, associate professor of animal sciences, Cameron Klein, doctoral student who performed most of the data analysis; and Crispin Kahesa and Julius Mwaiselage of the Ocean Road Cancer Institute.